Saturday, 14 April 2012


Genetic Link to Obesity
Dipti Shankar

In an article entitled, “Fat Chance”, (http://www.nytimes.com/2007/05/06/books/review/Bazelon.t.html 1) author Emily Bazelon posed the question “If you had to choose, would you rather be fat or blind?”2 Most people answered blind. One participant stated that “When you’re blind, people want to help you. No one wants to help you when you’re fat.”3. In 2007 researchers from the University of Oxford conducted a study wherein a genetic link to obesity was found4 . http://www.ox.ac.uk/research/medical_sciences/projects/fat_is_a_genetic.html
  
In the study, the genomes of people with and without diabetes were scanned. The scans revealed a variant of the FTO gene5, which functions in a group of enzymes to repair damaged DNA in the cell nucleus6 , increased the risk of diabetes by twenty-five percent in subjects with one copy, and fifty percent in subjects with two copies through an effect on body mass index7. Further research into the FTO variant found that subjects with two copies were approximately three kilograms heavier and had a seventy percent increased chance of being clinically obese than their zero copy gene variant counterparts8.

Figure 1- Graph confirming relationship between FTO gene and increased Body Mass Index9 (The Obesity Society, 2008)

This study by the University of Oxford is corroborated in the findings from a study by an article from the US National library of Medicine10. The study concluded that “common variation in the FTO gene is reproducibly associated with BMI and obesity from childhood into old age” 11 . The accepted notion that exercise and dieting will result in weightloss is refuted particularly strongly by Dr. Jeffrey Friedman who states that “Those who doubt the power of basic drives, however, might note that although one can hold one’s breath, this conscious act is soon overcome by the compulsion to breathe.”12
Additionally studies carried out with adopted children and twins that link genetics to obesity. A paper by Dr Albert Stunkard cited in an article (http://www.nytimes.com/2007/05/08/health/08fat.html?pagewanted=all ) by Gina Kolata 13 states that “there was a clear relation between the body-mass index of biologic parents and the weight class of adoptees, suggesting that genetic influences are important determinants of body fatness; and that childhood family environment alone has little or no effect”14. Osama Hamdy 15 affirms that “the high prevalence of obesity in the children of parents who are obese and the high concordance of obesity in identical twins suggest a substantial genetic component to the pathogenesis of obesity.”16 The findings of these studies establish that genetics accountable for seventy percent of weight variability in the population17. According to William Saletan18, this means that “weight is more strongly inherited than nearly any other condition, including mental illness, breast cancer or heart disease”19. It must be acknowledged however that obesity is due to both genetic and environmental factors and, as affirmed by the Public Library of Service20 “the prevalence of obesity likely reflects the exposure of genetically susceptible individuals to unhealthy secular trends in environmental and behavioral factors.” 21
Concisely, the research findings from Oxford University and numerous other studies show that genetics is indeed linked to obesity.
Reference List
1. New York Times, Bazelon E, 2007, “Fat chance,”  Viewed 16th March 2012, < http://www.nytimes.com/2007/05/06/books/review/Bazelon.t.html?fta=y&pagewanted=print>
2. Ibid
3. Ibid

4. University of Oxford, 2007,  “ Fat is a Genetic Issue,” Oxford, Oxfordshire, Viewed 14th March 2012, <http://www.ox.ac.uk/research/medical_sciences/projects/fat_is_a_genetic.html>

5. Ibid

6. Reece, J, Meyers, N, Urry, L, Cain, M, Wasserman, S, Minorsky, P, Jackson, R, Cooke, B 2011 “Campbell Biology-Ninth Edition Australian Version”, Pearson Education, China

7. University of Oxford, 2007,  “ Fat is a Genetic Issue,” Oxford, Oxfordshire, Viewed 14th March 2012, <http://www.ox.ac.uk/research/medical_sciences/projects/fat_is_a_genetic.html>

8. Ibid

9. Obesity society, 2008, “Graph confirming relationship between FTO gene and increased Body Mass IndexViewed 17th March 2012, <http://www.nature.com/oby/journal/v16/n4/full/oby200846a.html>

10. National Centre for Biotechnology Information, Frayling ,T, 2007, “A Common Variant in the FTO Gene is Associated with Body Mass Index and Predisposes Childhood and Adult Obesity,” U.S National Library of Medicine, Bethesda U.S,  viewed 17th March 2012, <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2646098/ >

11. Ibid

12. Kolata, G, 2007, “Rethinking Thin-The New Science of Weight Loss — and the Myths and Realities of Dieting- New York Times viewed 16th March 2012, <http://www.nytimes.com/2007/05/06/books/review/Bazelon.t.html>

13. Ibid

14.  Ibid

15. MedScape, Hamdy O, 2007, “Obesity” Viewed 17th March 2012, <http://emedicine.medscape.com/article/123702-overview#aw2aab6b2b3aa>

16. Ibid

17. Ibid

18. Slate, Saletan W, 2008, “Fat Chance-Obesity, genetics, and responsibility” Viewed 17th March 2012, <http://www.slate.com/articles/health_and_science/human_nature/2008/02/fat_>

19. Ibid

20. Public library of Service -Genetics, Scuteri A, 2007, “Genome-Wide Association Scan Shows Genetic Variants in the FTO Gene Are Associated with Obesity-Related Traits” Viewed 17th March 2012, http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.0030115
21. Ibid






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